feat: 完成资源系统导入设置类实现

- 新增 ImportSettings 基类
- 新增 TextureImportSettings 纹理导入设置类
- 新增 MeshImportSettings 网格导入设置类
- 新增 ResourcePath 资源路径类
- 完善 CMakeLists.txt 配置
- 新增对应单元测试 (45个测试用例)

engine/src/Resources/MeshImportSettings.cpp

@@ -0,0 +1,23 @@
+#include <XCEngine/Resources/MeshImportSettings.h>
+
+namespace XCEngine {
+namespace Resources {
+
+MeshImportSettings::MeshImportSettings() = default;
+
+MeshImportSettings::~MeshImportSettings() = default;
+
+Core::UniqueRef<ImportSettings> MeshImportSettings::Clone() const {
+    return Core::UniqueRef<ImportSettings>(new MeshImportSettings(*this));
+}
+
+bool MeshImportSettings::LoadFromJSON(const Containers::String& json) {
+    return false;
+}
+
+Containers::String MeshImportSettings::SaveToJSON() const {
+    return Containers::String();
+}
+
+} // namespace Resources
+} // namespace XCEngine